Process of removing impurities from impure aluminous material and producing nitrogen compounds therefrom.



0.- SERPEK.

PROCESS OF REMOVING IMPURITIE$ FROM IMPUEE ALUMINOUS MATERIAL AND PRODUCING NITROGEN GOMPOUHDS THEEEFBOM. APPLICATION FILED MAY 12, 1910.

Patgnted F9116, 1912.

4%{2/ 1U Lg lo cation.

20 alumina.

l tl ll dll hln area ion.

"SHEAR- SERPEK, F ZURICH, SWITZERLANI).

PRGGEQS G REMBVING- IME'URITIES FROM IMPURE ALUMINUUS M'ATERIAL AND PRQDUC'ING NITROGEN COMPOUNDS THEREFRUM.

Specification of Letters Patent.

Patented lt eb. it, 1 912.

Application tiled May 12, 1919. Serial No. 560,917.

To all whom it may concern:

it kniinvn that l, Orronan Snarnma subject of the Austro-Hungarian Emperor,

at 4-5 'lodistrasse, Zurich, Switzerltnd, have invented new and useful improvements in Processes of Removing Impurities from 'ln'ipurc Aluininous Material and Prod ring Nitrogen Con'ipounds There from, or" which the following is a spcciti- .i have d'scov-ered that when impure with carbon and the mixture heated in the presence ot nitrogen, the impuritles containcd in the alut-ninous material, especially silica, alkaline earths and allralis, canhe va porired and that this eyaporation takes place at temperatures below those which are necessary for vaporiabg or even melting 'lhus 1600- C. the impurities may be rcnmvcd by passing the nitrogen rather i through the mass. At this tcnip the formation of aluminum nitrid b take place.

s to in ordhat the reaction may be quickly and t'hm-ougily efi'ci'rted. temperatures 01' (The tem- 1706 to 1800 (l. are sufficient. pcraturcs are uniformly determined by means of ll auncfs optical pyrometer). A. further of the temperature accelerates the evaporation and the formation of nitrid,

without in any way substantially altering.

the invention. The temperature may without hcsitatmn be increased considerably, as

.35 the nitrid is scarcely volatile even in the electric are, so that there can be no loss of nitrid. According to the period of the heating and the degree of the temperature, nitrids are obtained, which contain up to 40 ill-,4 of nitrogen, and thus may be regarded as chemically pure. By treating such pure nitrids with water under pressure, pure alumina is obtained with ammonia. as a byproduct in. accordance with the reaction to formula or equation:

The alumina thus obtained can be at once employed in the manufacture of aluminum,

in which, as is well known only chemically as ever, can be easily separated from the nitrid l aluminous material such as bauxite is mixed its axis when desired.

50% of volatile mineral matters, that is to.

say, clays which could notbe employed in the production of alumina according to the previous methods, particularly on account of the disproportionately large consumption of expensive decomposing chemicals (soda, caustic soda).

The heating devices adopted are such as to allow of the lost heat from other processes being advantageously employed, whereby the actual evaporation can be carried on almost entirely iuthezone of lost heat, so that only the alumina freed from its ballast requires to be exposed to the direct action of the higher temperature.

A preferred form of apparatus for carrying out the above described process is illustrated in the annexed drawing, in which Figure 1 is a longitudinal section of a furnace, and Fig. 2 is across section of one half of the apparatus taken on the line 2-2 of Fig. 1.

In the drawing, A represents a metallic casing, consisting of iron for instance, B is a lining of refractory brick work, and C is another lining consisting of aluminum nitrid. This second lining is coated on its inner side with a tube or cylinder E consisting of a material which is a conductor of electricity, such as carbon. The electriccurrent is supplied to the said conductor by electrodes 1*,F which may also consist of carbon or they may be of copper. Gases consisting of, or containing'nitrogcn may be conveyed through the furnace in any desired manner. Means may be provided (not. shown) to turn the whole apparatus around At the i mcr side of the said conductor 1), projections (l may be providedto assist in producing an intimate mixture of the material to be treated.

The ammonia obtained in this process an important valuable by-product, which contributes substantially to rendering the process profitable.

I claim 1. The process of removing impurities from impure aluminous material containing silica and producing nitrogen compounds therefrom which comprises mixing such.

aluminous material with carbon and e ating the mixture in the presence of nitrogen to a temperature substantially below that of the electric arc. Y

2. The process of removing impurities from impure aluminous material containing silica and producing nitrogen compounds 5 therefrom which com rises mixing such alu- 25 temperature of about 1600 to 1800 C.

' a The process of treating aluminous material containing impprities capable of formmg volatile nitrogen compounds which comcarbon and heating the mixture in the presence of nitrogen to a temperature not exceeding 1800 C.

6. The process of treating aluminous ma- 4 terial containing impurities capableof forming volatile nitrogen compounds which comprises mixing such aluminous material with carbon and heating the mixture in the presence of nitrogen to a temperature of about 1600 to 1800 C.

In testimon whereof I aflix my signature in presence 0 two witnesses. I

- OTTOKAR SERPEK'.

Witnesses:

ALLAN MACFARLANE,

AUGUSTE J nor. 

